The present invention is directed to a locking centrifuge rotor cover assembly.
Conventional centrifuges typically include a housing with a centrifuge chamber, a rotor which supports the samples to be centrifuged, and a lid which is movable between an open position which accommodates access to the rotor and a closed position which encases the rotor and chamber. A rotor cover is often used to contain the contents of the centrifuge rotor during centrifugation. During normal operation, the containment of a liquid sample is secured when the sample is placed within a sealed sample tube, and thereafter covering the rotor with the rotor cover. However, the sample tube may be mishandled or have a defect which results in the rupture of the tube during high speed centrifugation, thus causing the sample liquid to become aerosolized and escape from the rotor if it is not properly sealed or covered. Accordingly, the rotor cover serves to enhance the containment of the samples. Also, in combination with the rotor, the cover forms a smooth surface that isolates the sample tubes from windage forces as well as reducing windage drag on the rotor.
In conventional centrifuges, the rotor cover has been designed as a separate unit from the centrifuge which requires manual attachment to the rotor for each use. Typically, the rotor cover includes a captive nut that is free to rotate, and which is screwed onto a threaded post at the center of the rotor to attach the cover to the rotor. Examples of this type of rotor cover design are found in U.S. Pat. Nos. 4,202,487, 4,360,151, 4,850,951, and 4,412,830, incorporated herein by reference.
The effectiveness of the use of a separate rotor cover, unfortunately, depends on the centrifuge operator remembering to attach the cover and completely tighten the nut. In the event of a human error where the cover is left off of the rotor, the samples could possibly be destroyed and the machine contaminated. In addition, the separate rotor cover takes up valuable laboratory counter space when it is removed from the machine, and can also be possibly misplaced.
It is therefore an object of the present invention to provide a centrifuge rotor cover which is retained within the centrifuge by coupling it to the lid or door of the centrifuge, thus obviating the need for separate manual attachment to the rotor.
It is another object of the present invention to provide a locking rotor cover wherein the cover is automatically attached to the rotor through the closing of the centrifuge lid or motion of the rotor, and thereafter allowing the cover to freely rotate with the rotor.
It is yet another object of the present invention to provide a rotor cover having a self-locking and un-locking centrifugal locking hub wherein the locking force increases with the rotational speed of the rotor.